It is known that polymers can be obtained by reacting bis epoxides with diamines. The polymers are curable by cross-linking to form solid resins which are useful as impregnating agents, glues, and moulding compositions. A continual search is going on for resins of this general type with improved and advantageous properties.
There have also, in the past, been efforts at preparing polyphosphates and polyphosphoramidates from bis-epoxy compounds: see U.S. Pat. Nos. 2,732,367; 2,826,592 and 2,856,369, and Sander & Steininger: "Reviews in Macromolecular Chemistry", Vol. 3 (1968), pp. 11-13. There has not, however, as far as is known, been any production of polymers from epoxides and phosphorus-containing bispiperazides.
The object of the present invention is to provide novel epoxy resins. Another object of the invention is to provide epoxy resins having non-flammable and flame-retardant properties.